There is a recognized problem with cracking of masonry walls due to the expansion and contraction of the walls and the uneven settling of the footings. Various methods have been tried for solving this problem. Also, there is a need for an improved guide for assuring that the wall joints are plumb and for finishing wall edges. Current practice in this regard utilizes a short length of wooden or metal bar which is moved vertically along the wall edge to simply provide a guide for finishing the wall edge after which it is removed. This prior art practice is time consuming and leads to jagged control joint edges.
Some of the past practices in attempting to prevent cracking of masonry walls have included horizontal and vertical reinforcements in the mortar, a practice which has not been very effective. Other approaches have utilized resilient members between rows of blocks. Such a suggestion is found in U.S. Pat. No. 2,869,356 and U.S. Pat. No. 3,099,110. The resilient members in these patents are cruciform in shape to inter fit with grooves in the masonry blocks. Another attempt has been through the utilization of asphalt impregnated horizontal sheets which are used in lieu of mortar and may be nailed to an interior sheet of wall board. Such a method is shown in U.S. Pat. No. 2,239,127.
Other prior art suggestions in combating cracking caused by expansion contraction and uneven settling of footings has utilized rubber sealing joints and caps. These have been suggested in U.S. Pat. No. 3,508,369; U.S. Pat. No. 2,016,968; U.S. Pat. No. 3,760,544; and U.S. Pat. No. 5,168,683.